U.S. patent number 5,004,567 [Application Number 07/222,302] was granted by the patent office on 1991-04-02 for process for producing fluorine-containing aliphatic carboxylic acids.
This patent grant is currently assigned to Tosoh Corporation. Invention is credited to Osamu Miyano, Hideo Shuyama, Mitsuru Takahashi, Yukihiro Tsutsumi.
United States Patent |
5,004,567 |
Takahashi , et al. |
April 2, 1991 |
Process for producing fluorine-containing aliphatic carboxylic
acids
Abstract
Process for producing fluorine-containing aliphatic carboxylic
acids having the general formula of Y--R.sub.f --Y' as defined
herein by reaction of fluorine-containing aliphatic halogen
compounds having the general formula of X--R.sub.4 --X' as defined
herein with carbon dioxide under the presence of zinc in an organic
solvent and hydrolysis of the reaction product, wherein the
improvement comprises controlling the concentration of carbon
dioxide in the organic solvent at a level of 0.3 to 5 mol/l.
Inventors: |
Takahashi; Mitsuru (Yamaguchi,
JP), Shuyama; Hideo (Yamaguchi, JP),
Miyano; Osamu (Yamaguchi, JP), Tsutsumi; Yukihiro
(Yamaguchi, JP) |
Assignee: |
Tosoh Corporation (Yamaguchi,
JP)
|
Family
ID: |
27312205 |
Appl.
No.: |
07/222,302 |
Filed: |
July 22, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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110017 |
May 27, 1986 |
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866839 |
Oct 13, 1987 |
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Foreign Application Priority Data
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May 27, 1985 [JP] |
|
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60-112219 |
Nov 29, 1985 [JP] |
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60-269078 |
Dec 27, 1985 [JP] |
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60-292438 |
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Current U.S.
Class: |
554/153; 554/130;
554/226; 554/75; 562/520; 562/551; 562/596 |
Current CPC
Class: |
C07C
51/15 (20130101); C07C 51/15 (20130101); C07C
57/54 (20130101); C07C 51/15 (20130101); C07C
55/32 (20130101); C07C 51/15 (20130101); C07C
57/52 (20130101); C07C 51/15 (20130101); C07C
53/21 (20130101) |
Current International
Class: |
C07C
51/15 (20060101); C07C 051/15 (); C11C
003/00 () |
Field of
Search: |
;562/551,596
;260/408 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2555630 |
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Jun 1976 |
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DE |
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2848197 |
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May 1980 |
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DE |
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2708751 |
|
Nov 1980 |
|
DE |
|
2374287 |
|
Jul 1978 |
|
FR |
|
1539300 |
|
Jan 1979 |
|
GB |
|
1581891 |
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Dec 1980 |
|
GB |
|
Primary Examiner: Evans; J. E.
Attorney, Agent or Firm: Sughrue, Mion, Zinn Macpeak &
Seas
Parent Case Text
This is a continuation of application Ser. No. 110,017 filed May
27, 1986, which is a continuation of application Ser. No. 866,839
filed Oct. 13, 1987, both abandoned.
Claims
What is claimed is:
1. A process for producing a fluorine-containing aliphatic
carboxylic acid having general formula (II) from a
fluorine-containing aliphatic halogen compound having general
formula (I) which process comprises the reaction of (I) at from
0.degree.-100.degree. C. with carbon dioxide in the presence of
1-10 equivalents of powdered zinc per equivalent of atoms of
halogen other than fluorine in (I) in an organic solvent selected
from the group consisting of dimethyl formamide,
N-methylpyrrolidone, N,N-dimethylacetamide and dimethylsulfoxide
followed by hydrolysis of the reaction product:
where, in formulae (I) and (II), X and X' independently denote a
fluorine, chlorine, bromine or iodine atom, but X and X' do not
both represent fluorine atoms at the same time, Y and Y' are
carboxyl groups which substitute and combine at the combining site
of X and X' in (I), and R.sub.f is a saturated or unsaturated
fluorine-containing straight or branched chain aliphatic group
which contains 1 to 20 carbon atoms when either X or X' is a
fluorine atom while otherwise R.sub.f contains 3 to 20 carbon
atoms, and when X or X' is a fluorine atom, the corresponding Y or
Y' is also a fluorine atom, which process involves controlling the
concentration of carbon dioxide in the organic solvent at a level
of 0.3 to 5 mol/l.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing
fluorine-containing aliphatic carboxylic acids. More particularly,
this invention provides a convenient and effective process for
producing the mentioned acids from fluorine-containing aliphatic
halogen compounds as starting material. Fluorine-containing
aliphatic carboxylic mono- and di-carboxylic acids are useful from
their chemical and physiological properties particularly as
surfactant, water and oil repellent agent, medicine, agricultural
chemical, and the synthetic intermediates thereof. Furthermore,
they are useful materials for industrial applications as monomer
for producing fluorine-containing polymers of various kinds, such
as, for example, for paint materials and for resists employed in
the production of LSI's, etc.
2. Description of Prior Arts
Conventional processes of synthesizing fluorine-containing
aliphatic carboxylic acids are roughly classified into two groups.
One group involves the electrolytic fluorination of aliphatic
halogen compounds, and the other starts from a fluorine-containing
aliphatic halogen compound.
Among them, processes which utilize the reaction of
fluorine-containing aliphatic halogen compounds with carbon dioxide
in the presence of metal is known to be relatively readily
accessible. They include processes using lithium or magnesium as
disclosed in J. Am. Chem. Soc., 73, 3158 (1951); J. Fluorine Chem.,
4, 247 (1974); J. Org. Chem., 33, 280 (1967) and Chem. Abs., 53,
6987g: also included is a process which employs zinc alone or a
metal couple of zinc and other metal as described in Japanese
Laid-Open Patent Application No. Sho 53-77008. Further, a process
has been proposed in which the reaction is carried out with zinc
powder under the influence of ultrasonic wave. Furthermore, a
process in which a fluorine-containing aliphatic halogen compound
is made to react with carbon monoxide in the presence of
palladium.
However, these processes mentioned above do not suffice to be
satisfactorily employed in industry. In the process using magnesium
or lithium, the fluorine-containing organic compound produced as
intermediate is very unstable and therefore the reaction should be
carried out at a low temperature, say -100.degree. or -40.degree.
C., and the carboxylic acid can be obtained only with a low
yield.
With the processes using zinc metal, a very low yield is expected
when zinc is used alone. When zinc is used together with another
metal to form a metal couple, the conversion rate of the raw
material as well as the yield of carboxylic acid aimed at are
improved, but the yield itself is still too low to attain an
efficient process for commercial production. In addition, the metal
couple of zinc and other metal should be prepared in advance, and
it is difficult to operate the process with a high reproducibility
and therefore a constant reproducible yield is difficult to
obtain.
With the process in which ultrasonic wave is irradiated in the
presence of zinc powder, a high power ultrasonic wave generator is
difficult to obtain and a low yield is expected. Therefore it is
not an effective process from the point of industrial processes. In
the process which involves carbon monoxide using palladium as
catalyst, the expense of palladium catalyst and the high toxicity
of carbon monoxide prevent the process from being advantageously
used as an industrial synthetic method.
As has been mentioned above, the conventional processes directed to
the production of fluorine-containing aliphatic carboxylic acids
starting from fluorine-containing aliphatic halogen compounds
suffer from the following problems:
(1) reaction conditions are difficult to set up;
(2) yield is low; and
(3) reaction is complicated to operate.
SUMMARY OF THE INVENTION
The present invention has its object in dissolving these problems.
More particularly, this invention intends to provide a process in
which fluorine-containing aliphatic carboxylic acids can be
produced from fluorine-containing aliphatic halogen compounds used
as starting material under a mild condition in a simple and
convenient operation and with a high yield.
To overcome difficulties of the prior art processes, the present
inventors intended to raise the efficiency in the production of
fluorine-containing aliphatic carboxylic acids by the reaction of
fluorine-containing aliphatic halogen compound with carbon dioxide
in the presence of zinc. Through our intensive investigations we
found that the yield of the product is largely influenced by the
concentration of carbon dioxide in the reaction system, and at last
reached the completion of the present invention.
In the reaction of a fluorine-containing aliphatic halogen compound
with carbon dioxide in the presence of zinc, it is generally
considered that a reaction intermediate is produced at first which
then reacts with carbon dioxide to form a zinc salt of the
fluorine-containing aliphatic carboxylic acid. In case the reaction
intermediate is unstable, competition arises with side reactions of
the possible decomposition reactions, thus leading to a lowered
selection rate of the carboxylic acid aimed at. Therefore, an
increased concentration of one of the reactants, carbon dioxide, is
considered to be effective to raise the selection rate for the
carboxylic acid aimed at, though the conversion rate of the raw
material can not be increased. With this consideration in mind,
correlation between the yield and the concentration of carbon
dioxide in the reaction solvent was thoroughly investigated. It was
surprising to find a sudden rise of yield of the carboxylic acids
aimed at when the concentration of carbon dioxide was increased
above a certain level. Namely, when the concentration of carbon
dioxide was increased to 0.3 mol/l or more, carboxylic acids aimed
at could be produced with a high yield. Thus, it was made clear
that increase in the concentration of carbon dioxide improved
conversion rate unexpectedly as well as selection rate. Thus it is
assumed that the increase of the concentration of carbon dioxide
not only produces a favorable effect based on the chemical reaction
kinetics, that is attained by increasing the concentration of a
reactant involved in one reaction of competing reactions, but also
produces some change in physical properties such as polarity or
basicity of the whole reaction system, with the result that
stability of a reaction intermediate is increased and thus the
producing rate thereof is increased, although the reason why such
effects are obtained by increasing the concentration of carbon
dioxide is not clear.
In short, the present invention relates to a process for producing,
from a fluorine-containing aliphatic halogen compound having a
general formula (I), a fluorine-containing aliphatic carboxylic
acids having a general formula (II) by the reaction of (I) with
carbon dioxide under the presence of zinc in an organic solvent
followed by hydrolysis of the reaction product,
where, in the formula (I) and (II), X and X' independently denote a
fluorine, chlorine, bromine, or iodine atom, but X and X' do not
represent fluorine atoms at the same time, Y and Y' are carboxyl
groups which substitute and combine at the combining site of X and
X' in (I), and R.sub.f is a saturated or unsaturated
fluorine-containing aliphatic group of a straight or branched chain
which contains 1 to 20 carbon atoms when either X or X' is a
fluorine atom while otherwise R.sub.f contains 3 to 20 carbon
atoms, and when X or X' is a fluorine atom, the corresponding Y or
Y' is also a fluorine atom, wherein the improvement comprises
controlling the concentration of carbon dioxide in an organic
solvent at a level of 0.3 to 5 mol/l.
DETAILED DESCRIPTION OF THE INVENTION
Hereinbelow the present invention will be described in detail.
We can show various kinds of fluorine-containing aliphatic halogen
compounds which are expressed by the general formula (I) and used
for the process of this invention. They include
perfluoroalkylhalogen compounds of straight or branched chain, for
example, CF.sub.3 (CF.sub.2).sub.p X, (CF.sub.3).sub.2
CF(CF.sub.2).sub.p X, or ##STR1## and those of which some fluorine
atoms in the molecular chain are substituted by hydrogen atoms such
as, for example, CF.sub.3 CH.sub.2 CF.sub.2 X, HCF.sub.2
(CF.sub.2).sub.p X or CF.sub.3 (CF.sub.2).sub.p CH.sub.2 X, where X
denotes chlorine, bromine or iodine atom, and p and q express zero
or a positive integer.
Further, R.sub.f, a fluorine-containing aliphatic group, in the
general formula (I) may contain unsaturated bond such as a double
bond between two carbon atoms, and represent a perfluoro substance
or that of which a part of fluorine atoms is substituted by
hydrogen atoms.
We can demonstrate the following substances which belong to the
above-mentioned category: CF.sub.2 =CF(CF.sub.2).sub.p X, ##STR2##
and F.sub.2 C=CHX, H(F)C=C(F)X, H(F)C=C(H)X, H.sub.2 C=C(F)X where
X, p and q have the same meaning as above.
F.sub.2 C=C(R)X, F(R)C=C(F)X, H(R)C=C(F)X F(R)C=C(H)X, H(F)C=C(R)X,
H(R.sub.f ')C=C(F)X F(R.sub.f ')C=C(H)X, H(F)C=C(R.sub.f ')X,
H.sub.2 C=C(R.sub.f ')X R.sub.2 C=C(F)X, R.sub.f '(R)C=C(F)X,
R.sub.f '.sub.2 C=C(H)X R.sub.f '(R)C=C(H)X, F(R)C=C(R)X, R.sub.f
'(F)C=C(R.sub.f ')X R.sub.f '.sub.2 C=C(R.sub.f ')X, R.sub.f
'(R)C=C(R)X, R.sub.2 C=C(R.sub.f ')X R.sub.f '.sub.2 C=C(R)X,
R.sub.f '(R)C=C(R.sub.f ')X, R(F)C=C(R.sub.f ')X R.sub.f
'(F)C=C(R)X, R.sub.f '(H)C=C(R.sub.f ')X, R.sub.f '(H)C=C(R)X
R(H)C=C(R.sub.f ')X
where R is an alkyl group, R.sub.f ' is a fluorine-containing alkyl
group and X is the same as above.
In addition, perfluorodihalogen compounds having a straight or
branched chain expressed by the following formulae: ##STR3## and
dihalogen compounds in which fluorine atoms in the fluoroalkyl
chain are partly substituted by hydrogen atoms expressed by the
following formula: ##STR4## are also employed for the object of
this invention, where X and X' denote chlorine, bromine, or iodine
atoms independently, l is an integer 3 or more, m is an integer 1
or more, and p and q have the same meaning as above.
Furthermore, fluorodihalogen compounds of which R.sub.f group in
the general formula (I) has unsaturated bond such as the double
bond between two carbon atoms are also employed for the object of
this invention. These compounds may be cited as follows: ##STR5##
where X, X', p, and q have the same meaning as above.
Thus, a number of substances can be used as fluorine-containing
aliphatic halogen compounds expressed by the general formula (I),
but the number of carbon atoms constituting the fluorine-containing
aliphatic group is preferably equal or less than 20 to maintain a
practically high solubility of the compound in the solvent for
reaction.
It is required in the reaction of the present invention that the
concentration of carbon dioxide in the organic solvent be equal or
greater than 0.3 mol/l. If the concentration is less than the
level, the high yield this invention aims at can not be
attained.
The upper limit of the concentration of carbon dioxide may be set
practically at 5 mol/l, because the effect to improve the yield is
remarkably diminished at a higher level. Usually, concentration of
carbon dioxide in an organic solvent changes according to the
nature of solvent and the temperature. Therefore, the mentioned
concentration can be obtained by selecting the solvent or the
temperature at which the reaction takes place. For more
convenience, the desired concentration can be realized using a
pressure applying apparatus such as an autoclave to raise the
carbon dioxide pressure at a level higher than the normal pressure.
This can be done irrespective of the solvent and the temperature of
reaction. For example, when dimethylsulfoxide (hereinafter
designated as DMSO) is used, concentration of carbon dioxide at
0.degree. C. and under the normal pressure is 0.13 mol/l, but when
the pressure is increased to 5 kg/cm.sup.2 (absolute pressure) with
a pressure applying apparatus the concentration can be increased to
0.6 mol/l (at 35.degree. C.). If dimethylformamide (hereinafter
called DMF) is used, the carbon dioxide concentration which is 0.23
mol/l at 20.degree. C. and under the normal pressure can be
increased using a pressure apparatus to 5 kg/cm.sup.2 (absolute
pressure to 0.85 mol/l at 35.degree. C.
Zinc to be used in the process of above reactions should preferably
be in the powdery form of which the mean diameter of particles be
in the range from 0.1 to 100 .mu.m. If the particle size is smaller
than 0.1 .mu.m in diameter, the particles are hardly removed when
the reaction is completed, while the yield of reaction is decreased
for the size larger than 100 .mu.m in diameter. Thus, the mean
diameter of particles is particularly preferred to be 1-50 .mu.m
from the standpoint of the yield of reaction and the easy
operation.
Commerical zinc may be used without any pretreatment, but a smaller
amount of the metal suffices for the purpose if it is
surface-treated beforehand. For the surface treatment, the method
described in HorbenWeyl, 13(2a), p.570-p.574, and p.815 may be
applied. Namely the metal is treated beforehand with a mineral or
acetic acid, for example, or by forming a metal couple with another
metal such as copper, lead, cadmium, and mercury for ordinary
cases.
Suitable amount of the zinc powder may be at least in an amount
equivalent to halogen atoms other than fluorine atoms in the
fluorine-containing aliphatic halogen compounds in the raw
material. If the amount of zinc powder is less than an equivalent
amount to the halogen atoms, the yield is naturally lowered and
also reproducibility of the yield is lost for the product
carboxylic acids. On the contrary, when the amount of zinc is too
much, for example 10 times as much in equivalent, only a small
increased effect can be expected. Thus, it is recommended to use
zinc powder in an amount 1 to 10 times as much as the halogen atoms
other than fluorine atom in the fluorine-containing aliphatic
halogen compounds as raw material. More preferably the amount
should be 2 to 10 times as much in equivalent.
The most preferred solvents to be used in the present invention are
aprotic polar solvents. They include, for example, DMF, DMSO, N,
N-dimethylacetamide, tetramethylurea, hexamethylphosphoramide,
sulforane, N-methylpyrrolidone, nitrobenzene, nitromethane,
acetonitrile, propylene carbonate, tetrahydrofurane, dioxane,
ether, diglyme, triglyme and pyridine. Among them, more preferred
from the reaction yield are DMF, DMSO, N-methylpyrrolidone, N,
N-dimethylacetamide, tetramethylurea and
hexamethylphosphoramide.
The reaction of this invention can take place in a wide range of
temperature, but in ordinary cases a temperature range 0.degree. to
150.degree. C., preferably 0.degree. to 100.degree. C., is
selected. At a temperature below 0.degree. C. the process is not
practical, because the raw material halogen compounds require a
very long reaction time to obtain a high conversion rate, though
carbon dioxide in the solvent can easily be maintained at a high
concentration. On the other hand, if the temperature exceeds
150.degree. C., a high pressure is needed to maintain a
predetermined high concentration of carbon dioxide in the solvent
and, in addition, the increased rate of side reactions decreases
the selection rate to the route to the carboxylic acids aimed
at.
The reaction of fluorine-containing aliphatic halogen compound is
proceeded in an organic solvent in the presence of suspended zinc
by contact with carbon dioxide at a predetermined temperature.
Since the concentration of carbon dioxide in the reaction solvent
is important in the present invention, the concentration must be
maintained throughout the reaction at a value not lower than 0.3
mol/l. For this end, the concentration of carbon dioxide is either
set up initially at a value high enough not to fall below 0.3 mol/l
throughout the reaction, or supplied continually to compensate the
consumed amount. The raw material halogen compound should
preferably be added continually to a mixture of the reaction
solvent and zinc which is kept at a predetermined temperature and
contains carbon dioxide at a predetermined concentration.
The more slowly the raw material halogen compound is added, the
better is the yield of the final product. But the most preferred
speed is in the range from 0.05 to 10 mol/hr per liter of solvent.
A speed below 0.05 mol/hr is not practial because it takes too long
a time for the addition. On the contrary, an adding speed exceeding
10 mol/hr gives rise to a remarkable decrease of the yield. When
the addition is made, the reaction time will be 30 min to 48 hr
after the completion of addition of fluorine-containing aliphatic
halogen compound.
However, if the raw material halogen compound is in the form of
solid and is not so soluble to the reaction solvent as to adopt the
addition method as mentioned above, it is also possible to proceed
the reaction by adding the solvent to a mixture of said halogen
compound and zinc under the atmosphere of carbon dioxide. In this
case, 30 min to 48 hr suffice for the reaction after the addition
of the solvent and the establishment of the reaction
temperature.
Thus, fluorine-containing aliphatic halogen compound is allowed to
react with carbon dioxide in the presence of zinc, and the product
is hydrolyzed to obtain the aimed fluorine-containing aliphatic
carboxylic acid. The hydrolysis is readily conducted by mere
contact with a mineral acid such as hydrochloric, sulfuric and
nitric.
The process of the present invention is very useful to convert
fluorine-containing aliphatic halogen compounds into
fluorine-containing aliphatic carboxylic acids with a high yield
without producing a least amount of by-products. Consequently, in
addition, the operation to recover unreacting raw material will
probably be unnecessary, the object product will be purified in a
simpler process and can be isolated more readily. Thus, the process
is very useful for the industrial purposes.
EXAMPLES
The present invention will be described more in detail by referring
to Examples and Comparison Examples hereinbelow, but it should be
understood the invention is not limited thereto.
EXAMPLE 1
Into an electromagnetic agitation autoclave of 200 cc capacity
which was provided with an inlet for carbon dioxide gas and a
pressure inlet for perfluoroalkyl iodide, 19.6 g (or 0.3 gram atom)
of zinc dust (having 15 .mu.m mean particle diameter) which had
been washed beforehand with 0.5N hydrochloric acid and dried was
added and the inside of the autoclave was heated to 35.degree. C.
by the outer heating. The pressure of carbon dioxide was made 6.0
kg/cm.sup.2 (absolute pressure) with a constant pressure device.
The pressure was kept at the constant value throughout the
treatment. Then 80 ml of DMF was pumped to the autoclave under
stirring by a liquid delivery pump. The DMF, as soon as it was
transferred to the autoclave, began to dissolve carbon dioxide and
finally reached a saturation concentration (1.0 mol/l) at the
carbon dioxide pressure (6.0 kg/cm.sup.2, absolute pressure) in the
gaseous phase. Then a mixture of 54.6 g (or 0.1 mol) of
perfluorooctyl iodide and 3 ml of DMF was transferred into the
autoclave under pressure with the liquid delivery pump in an hour
and 15 min at a constant speed. Agitation was continued for 2 hr
and 45 min at the same temperature. Then the pressure of carbon
dioxide in the autoclave was released to the atmospheric pressure
to terminate the reaction.
The excess of zinc (13 g) was removed by filtration from the
reaction mixture and the solvent DMF was partly removed by
distillation, to concentrate the filtrate. This concentrate was
poured into a 6N aqueous hydrochloric acid to hydrolyze the
reaction intermediate. Concentrated sulfuric acid was added and the
mixture was distilled, to obtain 42.7 g of C.sub.8 F.sub.17
COOH.
A yield of 92% was obtained. The product melted at
70.degree.-71.degree. C. and boiled at 107.degree. C./17 mmHg.
EXAMPLES 2-7 AND COMPARISON EXAMPLE 1
The pressure of carbon dioxide and the reaction temperature was set
up as shown in Table 1. The process was the same as in Example 1,
except that the carbon dioxide concentration in DMF was varied. In
Comparison Example, carbon dioxide was kept at the normal pressure
and the concentration of carbon dioxide in DMF was 0.20 mol/l.
Results are shown in Table 1.
TABLE 1 ______________________________________ Concen- Temperature
Pressure tration of reaction of CO.sub.2 of CO.sub.2 Yield
(.degree.C.) (abs.kg/cm.sup.2) (mol/l) (%)
______________________________________ Example 2 35 2.0 0.35 86
Example 3 35 3.5 0.60 90 Example 4 60 6.0 0.73 91 Example 5 15 6.0
1.40 94 Example 6 25 6.0 1.25 94 Example 7 35 11.0 1.90 96
Comparison 25 Normal 0.20 72 Example 1 Pressure
______________________________________
COMPARISON EXAMPLE 2
A mixed gas of carbon dioxide and nitrogen (of which carbon dioxide
was 16.7 vol %) was made 6 kg/cm.sup.2. Other conditions were the
same as in Example 1. The concentration of carbon dioxide in DMF
was 0.16 mol/l. C.sub.8 F.sub.17 COOH was obtained with a yield of
68%.
EXAMPLE 8
The procedure was the same as in Example 1, except that the amount
of zinc employed was 7.85 g (or 0.12 gram atom) instead of 19.6 g
(or 0.3 gram atom). As a result, the yield of C.sub.8 F.sub.17 COOH
was 80%.
EXAMPLE 9
The procedure was the same as in Example 1, except that the amount
of zinc employed was 39.2 g (or 0.6 gram atom) instead of 19.6 g
(or 0.3 gram atom). As a result, the yield of C.sub.8 F.sub.17 COOH
was 93%.
EXAMPLES 10-12
The procedure was the same as in Example 1, except that the
solvents indicated in Table 2 were used in place of DMF. Results
are shown in Table 2.
TABLE 2 ______________________________________ Pressure
Concentration Ex- of CO.sub.2 of CO.sub.2 Yield ample Solvent (abs.
kg/cm.sup.2) (mol/l) (%) ______________________________________ 10
N-Methyl- 6.0 0.8 87 pyrrolidone 11 N.N-dimethyl- 6.0 0.9 88
acetamide 12 Dimethyl- 6.0 0.7 82 sulfoxide
______________________________________
EXAMPLE 13
The same procedure as in Example 1 was followed except that 23.0 g
(or 0.35 gram atom, 15 .mu.m mean particle size in diameter) of
commercially available zinc was employed. C.sub.8 F.sub.17 COOH was
obtained with a yield of 92%.
EXAMPLE 14
The same procedure as in Example 1 was followed except that 44.6 g
(or 0.1 mol) of perfluorohexyl iodide was employed in place of 54.6
g (or 0.1 mol) of perfluorooctyl iodide and the reaction was
conducted at 25.degree. C. 33.5 g of C.sub.6 F.sub.13 COOH was
obtained with a yield of 92%. The product melted at
25.degree.-26.degree. C. and boiled at 72.degree. C./20 mmHg.
EXAMPLE 15
Into a 200 cc electromagnetic agitation type autoclave provided
with an inlet for carbon dioxide, 13.0 g (or 0.020 mol) of
perfluorodecyl iodide and 4.0 g (or 0.061 gram atom) of zinc powder
(15 .mu.m mean particle size in diameter) were introduced. The
temperature in the inside of the autoclave was cooled to 5.degree.
C. by the outer cooling. Carbon dioxide was introduced via a
constant pressure device to attain a pressure of 4 kg/cm.sup.2
(absolute pressure). While the content of the autoclave was being
agitated, 80 ml of DMF at the same temperature was introduced in 30
min.
The temperature inside the autoclave was elevated to 35.degree. C.
by the outer heating and agitation started. Pressure inside the
autoclave was elevated to 5.7 kg/cm.sup.2 which was maintained to
the completion of the reaction. At this moment, concentration of
carbon dioxide in DMF was 0.95 mol/l in the autoclave. Starting the
reaction with stirring at 35.degree. C., the pressure in the
autoclave was released to terminate the reaction after 5 hours.
Excess of zinc in the reaction mixture was removed by filtration
and the solvent DMF was partly removed by distillation to
concentrate the filtrate. Subsequently this concentrate was poured
into 6N aqueous hydrochloric acid to hydrolyze the reaction
intermediate. Further, the product was extracted with diethylether.
To the ether solution, a diazomethane solution in ether was added
to convert the product C.sub.10 F.sub.21 COOH into methyl ester and
the reaction yield was estimated by the gas chromatography using an
internal standard. Results showed a yield of 92% for the production
of C.sub.10 F.sub.21 COOH.
EXAMPLE 16
Into a 200 cc electromagnetic agitation type autoclave provided
with an inlet for carbon dioxide and a pressure inlet for 3, 3,
3-trifluoro-2-iodopropene was placed 19.6 g (or 0.3 gram atom) of
zinc dust (15 .mu.m mean particle size in diameter) which had been
washed with 0.5N aqueous hydrochloric acid and dried. The inside of
autoclave was heated to 35.degree. C. by the outer heating. The
pressure of carbon dioxide was elevated to 6.0 kg/cm.sup.2
(absolute pressure) with a constant pressure device and the
pressure of carbon dioxide in the autoclave was maintained
throughout the reaction period. Then 80 ml of DMF was introduced to
the autoclave with a liquid delivery pump under agitation. The DMF,
as soon as it was introduced in the autoclave, began to dissolve
carbon dioxide, at last to reach the saturation concentration (1
mol/l) under gaseous carbon dioxide phase pressure 6.0 kg/cm.sup.2
(absolute pressure).
Then a mixture of 22.2 g (or 0.10 mol) of 3, 3,
3-trifluoro-2-iodopropene and 10 ml of DMF was introduced under
pressure into the autoclave in 1 hour. Stirring was continued for
additional 2 hours at the same temperature and then the pressure in
the autoclave was released to the normal pressure to terminate the
reaction.
From the reaction mixture, excessive 13 g of zinc was removed by
filtration and the solvent DMF was partly removed and recovered by
distillation to concentrate the filtrate. The concentrate was
poured in a 6N aqueous hydrochloric acid to hydrolyze the reaction
intermediate. Then followed were the extraction with diethylether
and drying of the extract. By distilling the ether 11.5 g of
.alpha.-trifluoromethylacrylic acid was obtained (82% of yield).
The product was identified by comparing spectroscopic data with
those of standard substance in GLC, IR and NMR.
EXAMPLES 17-19
The carbon dioxide pressure and the reaction temperature were set
up as shown in Table 3. Procedure was the same as that in Example
16 except that the concentration of carbon dioxide in DMF was
varied. Results are shown in Table 3.
TABLE 3 ______________________________________ Temperature Pressure
Concentration of reaction of CO.sub.2 of CO.sub.2 Yield Example
(.degree.C.) (abs. kg/cm.sup.2) (mol/l) (%)
______________________________________ 17 35 2.0 0.35 76 18 60 11.0
1.35 84 19 35 11.0 1.90 85
______________________________________
EXAMPLE 20-22:
The procedure was the same as in Example 16, except that the
solvents indicated in Table 4 were used in place of DMF. Results
are shown in Table 4.
TABLE 4 ______________________________________ Pressure
Concentration Ex- of CO.sub.2 of CO.sub.2 Yield ample Solvent (abs.
kg/cm.sup.2) (mol/l) (%) ______________________________________ 20
N-Methyl- 6.0 0.8 75 pyrrolidone 21 N.N-Dimethyl- 6.0 0.9 78
acetamide 22 Dimethyl- 6.0 0.7 76 sulfoxide
______________________________________
EXAMPLE 23
The procedure employed in this example was the same as in Example
16, except that 17.5 g (or 0.1 mol) of 3, 3,
3-trifluoro-2-bromopropene (CF.sub.3 BrC.dbd.CH.sub.2) was used in
place of 3, 3, 3-trifluoro-2-iodopropene and the mixture after said
bromine compound was added was agitated for 24 hours. 8.4 g of
.alpha.-trifluoromethylacrylic acid was obtained with a yield of
60%.
EXAMPLE 24
The same procedure as that of Example 16 was employed, except that
23.0 g (or 0.35 gram atom) of commercial zinc (15 .mu.m mean
particle diameter) was used without any pretreatment. With a yield
of 80%, .alpha.-trifluoromethylacrylic acid was obtained.
EXAMPLE 25
To a mixed solution of 50 ml of DMF and 10 ml of acetic acid, was
added 0.6 g of copper acetate and the mixture was heated at
40.degree.-50.degree. C. Then 19.6 g (or 0.3 gram atom) of
commercial zinc powder was added to the mixture and agitated for 30
min. After cooled, the mixture was washed 4 times with 25 ml of DMF
to obtain zinc-copper couple.
The same procedure was followed as in Example 16, except that the
zinc-copper couple was used. As a result,
.alpha.-trifluoromethylacrylic acid was obtained with a yield of
80%.
EXAMPLES 26-29
The same procedure as that in Example 16 was followed, except that,
in place of 3, 3, 3-trifluoro-2-iodopropene, each 0.10 mol of 3, 3,
4, 4, 5, 5, 6, 6, 6-nonafluoro-2-iodohexene, 1, 2,
2-trifluoro-1-iodoethene, 1, 2-difluoro-1-iodo-3-methylpentene or
2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
9-hexadecafluoro-1-iodononene was employed. Corresponding .alpha.,
.beta.-unsaturated carboxylic acids were obtained. Each product was
identified by IR and NMR. Results are shown in Table 5.
TABLE 5 ______________________________________ Example Product
Yield (%) ______________________________________ 26 n-C.sub.4
F.sub.9 C(CO.sub.2 H).dbd. CH.sub.2 65 27 CF.sub.2 .dbd. CFCO.sub.2
H 80 28 CH.sub.3 CH.sub.2 CH(CH.sub.2)CF.dbd. CFCO.sub.2 H 74 29
n-C.sub.7 F.sub.15 CF.dbd. CHCO.sub.2 H 71
______________________________________
COMPARISON EXAMPLE 3
To a 300 ml 4-necked flask provided with an inlet tube for
introducing carbon dioxide, dropping funnel, reflux cooler (of
which coolant was dry ice-acetone) and a stirrer, were added 19.6 g
(or 0.3 gram atom) of zinc powder (15 .mu.m mean particle diameter)
which had been washed with 0.5N aqueous hydrochloric acid and then
dried and 80 ml of DMF. Carbon dioxide gas was introduced in a
speed of 45 ml/min for 30 min under the normal pressure
(Temperature was 25.degree. C., and the concentration of carbon
dioxide in DMF was about 0.2 mol/l). Subsequently, while carbon
dioxide being introduced at the same flow rate at 25.degree. C., a
mixture of 22.2 g (or 0.1 mol) of 2-iodo-3, 3, 3-trifluoropropene
and 10 ml of DMF was added in drops in an hour through the dropping
funnel. Agitation was continued at the same temperature for
additional 4 hours. Then excess of zinc was removed from the
reaction mixture and 5.6 g of .alpha.-trifluoromethylacrylic acid
(40% yield) was obtained in the same process as described in
Example 16.
COMPARISON EXAMPLE 4
The same procedure as that in Example 16 was followed, except that
the pressure 6 kg/cm.sup.2 in the inside of autoclave was produced
with a mixed gas of carbon dioxide and nitrogen (carbon dioxide
occupied 16.7 vol %) instead of carbon dioxide alone Concentration
of carbon dioxide in DMF was 0.16 mol/l. Yield of
.alpha.-trifluoromethylacrylic acid was 42%.
EXAMPLE 30
The same procedure as that in Example 16 was followed, except that
the amount of zinc was changed from 19.6 g (or 0.3 gram atom) to
7.85 g (or 0.12 gram atom). Yield of .alpha.-trifluoromethylacrylic
acid was 57%.
EXAMPLE 31
The same procedure as that in Example 16 was followed, except that
the amount of zinc was changed from 19.6 g (or 0.3 gram atom) to
39.2 g (or 0.6 gram atom) Yield of .alpha.-trifluoromethylacrylic
acid was 85%.
EXAMPLE 32
Into a 200 cc electromagnetic agitation type autoclave provided
with an inlet for carbon dioxide and a pressure inlet for
perfluoroalkyl diiodide, was placed 19.6 g (or 0.3 gram atom) of
zinc dust (15 .mu.m mean particle size in diameter) which had been
washed with 0.5N aqueous hydrochloric acid and dried. The inside of
autoclave was heated to 35.degree. C. by the outer heating. The
pressure of carbon dioxide was elevated to 6.0 kg/cm.sup.2
(absolute pressure) with a constant pressure device and the
pressure of carbon dioxide in the autoclave was maintained
throughout the reaction period. Then 80 ml of DMF was introduced to
the autoclave with a liquid delivery pump under agitation. The DMF,
as soon as it was introduced in the autoclave, began to dissolve
carbon dioxide, at last to reach the saturation concentration (1
mol/l) under gaseous carbon dioxide phase pressure 6.0 kg/cm.sup.2
(absolute pressure).
Then a mixture of 22.7 g (or 0.05 mol) of 1,
4-diiodo-perfluorobutane and 10 ml of DMF was introduced under
pressure into the autoclave in 1 hour. Stirring was continued for
additional 1 hour at the same temperature and then the pressure in
the autoclave was released to the normal pressure to terminate the
reaction.
From the reaction mixture, excessive 13 g of zinc was removed by
filtration and the solvent DMF was partly removed and recovered by
distillation to concentrate the filtrate. The concentrate was
poured in a 6N aqueous hydrochloric acid to hydrolyze the reaction
intermediate. Then followed the extraction with diethylether,
drying of the extract and the methyl esterification with
diazomethane. The yield of perfluoroadipic acid as estimated by gas
chromatography was 88%. The perfluroadipic acid and the dimethyl
esters thereof were identified by .sup.1 R, .sup.1 HNMR, and
.sup.19 F-NMR.
EXAMPLES 33-35
The same procedure as that in Example 32 was followed, except that
the pressure of carbon dioxide and the temperature of reaction were
set up as indicated in Table 6 and the concentration of carbon
dioxide in DMF was varied. Results are shown in Table 6.
TABLE 6 ______________________________________ Temperature Pressure
Concentration of reaction of CO.sub.2 of CO.sub.2 Yield Example
(.degree.C.) (abs. kg/cm.sup.2) (mol/l) (%)
______________________________________ 33 35 2.0 0.35 82 34 15 6.0
1.40 90 35 35 11.0 1.90 93
______________________________________
EXAMPLES 36-38
The same procedure as that in Example 32 was followed, except that
the solvents indicated in Table 7 were employed in place of DMF.
Results are shown in Table 7.
TABLE 7 ______________________________________ Pressure
Concentration Ex- of CO.sub.2 of CO.sub.2 Yield ample Solvent (abs.
kg/cm.sup.2) (mol/l) (%) ______________________________________ 36
N-Methyl- 6.0 0.8 85 pyrrolidone 37 N,N-Dimethyl- 6.0 0.9 87
acetamide 38 Dimethyl- 6.0 0.7 80 sulfoxide
______________________________________
EXAMPLE 39
The same procedure as that in Example 32 was employed, except that
1, 6-diiodoperfluorohexane was used as a perfluoroalkyldihalogen
compound in an amount of 27.7 g (or 0.05 mol). The perfluorosuberic
acid (HO.sub.2 C(CF.sub.2).sub.6 CO.sub.2 H) was obtained with a
yield of 85%. The product was identified by 1R, .sup.19 F-NMR and
.sup.1 H-NMR.
EXAMPLE 40
The same procedure as that in Example 32 was followed, except that
23.0 g (or 0.35 gram atom) of commercial zinc (15 .mu.m mean
particle diameter) which was not surface treated was used.
Perfluoroadipic acid was obtained with a yield of 84%.
EXAMPLE 41
To a mixed solution of 50 ml of DMF and 10 ml of acetic acid, was
added 0.6 g of copper acetate and the mixture was heated at
40.degree.-50.degree. C. Then 19.6 g (or 0.3 gram atom) of
commercial zinc powder was added to the mixture and agitated for 30
min. After cooled, the mixture was washed 4 times with 25 ml of DMF
to obtain zinc-copper couple.
The same procedure was followed as in Example 32, except that the
zinc-copper couple was used. As a result, perfluoroadipic acid was
obtained with a yield of 86%.
EXAMPLE 42
The same procedure as that in Example 32 was followed, except that,
as perfluoroalkyl dihalogen compound, 1, 6-dibromoperfluorohexane
was used in an amount of 23 g (or 0.05 mol). Perfluorosuberic acid
was obtained with a yield of 75%.
COMPARISON EXAMPLE 5
To a 300 ml 4-necked flask provided with an inlet tube for
introducing carbon dioxide, dropping funnel, reflux cooler and a
stirrer, were added 19.6 g (or 0.3 gram atom) of zinc powder (15
.mu.m mean particle diameter) which had been washed with 0.5N
aqueous hydrochloric acid and then dried and 80 ml of DMF. Carbon
dioxide gas was introduced in a speed of 45 ml/min for 30 min under
the normal pressure (Temperature was 25.degree. C., and the
concentration of carbon dioxide in DMF was about 0.2 mol/l).
Subsequently, while carbon dioxide being introduced at the same
flow rate at 25.degree. C., a mixture of 22.7 g of 1,
4-diiodoperfluorobutane and 10 ml of DMF was added in drops in an
hour through the dropping funnel. Agitation was continued at the
same temperature for additional 2 hours. Then excess of zinc was
removed from the reaction mixture and perfluoroadipic acid was
produced in the same process as described in Example 32. The yield
estimated to be 45%.
COMPARISON EXAMPLE 6
The Example for comparison was carried out in the same procedure as
in Comparison Example 5, except that the zinc dust in Comparison
Example 5 was replaced by the zinc-copper couple prepared in a
process similar to that in Example 41. Yield of perfluoroadipic
acid was 54%.
COMPARISON EXAMPLE 7
The same procedure as that in Example 32 was followed, except that
the pressure 6 kg/cm.sup.2 in the inside of autoclave was produced
with a mixed gas of carbon dioxide and nitrogen (carbon dioxide
occupied 16.7 vol %) instead of carbon dioxide alone. Concentration
of carbon dioxide in DMF was 0.16 mol/l. Yield of perfluoroadipic
acid was 50%.
EXAMPLE 43
The same procedure as that in Example 32 was followed, except that
the amount of zinc employed was changed from 19.6 g (or 0.3 gram
atom) to 7.85 g (or 0.12 gram atom). The yield of perfluoroadipic
acid was 65%.
EXAMPLE 44
The same procedure as that in Example 32 was followed, except that
the amount of zinc employed was changed from 19.6 g (or 0.3 gram
atom) to 30.2 g (or 0.6 gram atom). The yield of perfluoroadipic
acid was 90%.
* * * * *